[fouc]

Didn't ycombinator pick a number of startups with bad ideas or non-ideas and encouraged them to pivot? Or encourage new teams to form around a different idea?

For example Reddit's original team wanted to do a "My Mobile Menu", and also Aaron Swartz pivoted from Infogami to merging with Reddit.

I would almost count this partially under the "no idea" category.

[nl]

There's plenty of YC Companies that have changed their idea during YC, or pivoted completely during the program (I think Daniel Gross pivoted twice?)

I think YC expects most companies to modify what they are doing during the program.

But all of these things are very different to taking someone on board with no idea at all.